Electro-oxidation of carbon monoxide

Hayden BE, Murray AJ, Parsons R, Pegg DJ. 1996. UHV and electrochemical transfer studies on Pt(110)-(1 X 2) The influence of bismuth on hydrogen and oxygen adsorption, and the electro-oxidation of carbon monoxide. J Electroanal Chem 409 51-63. 

Knheiro ALN, Zei MS, Ertl G. 2005. Electro-oxidation of carbon monoxide and methanol on bate and Pt-modified Ru(10—10) electrodes. Phys Chem Chem Phys 7 1300. 

Anderson AB, Neshev NM. 2002. Mechanism for the electro-oxidation of carbon monoxide on platinum, including electrode potential dependence—Theoretical determination. J Electrochem Soc 149 E383-E388. 

Antolini E, Gonzalez ER (2010) The electro-oxidation of carbon monoxide, hydrogen/carbon monoxide and methanol in acid medium on Pt-Sn catalysts for low-temperature fuel cells a... 

Shi, C. and F.C. Anson (2001). Catalysis of the electro-oxidation of carbon monoxide by cobalt octaethylporphyrin. Inorg. Chem. 40(23), 5829-5833. 

Davies JC, Hayden BE, Pegg DJ, Rendall ME. The electro-oxidation of carbon monoxide on ruthenium modified Pt(l 1 1). Surf Sci 2002 496 110-20. 

Hayden BE, RendaU ME, South O. Electro-oxidation of carbon monoxide on well-ordered Pt(l 1 lySn surface alloys. J Am Chem Soc 2003 125 7738-42. 

The electro-oxidation of carbon monoxide on noble metal catalysts as revisited by real-time surface-enhanced Raman spectroscopy, Y. Zhang and M. J. Weaver, J. Electroanal. Chem., 1993, 354, 173. 

Watanabe M, Motoo S. 1975. Electro catalysis by ad-atoms. Part III. Enhancement of the oxidation of carbon monoxide on platinum by ruthenium adatoms. J Electroanal Chem 60 275. 

This section addresses the role of chemical surface bonding in the electrochemical oxidation of carbon monoxide, CO, formic acid, and methanol as examples of the electrocatalytic oxidation of small organics into C02 and water. The (electro)oxidation of these small Cl organic molecules, in particular CO, is one of the most thoroughly researched reactions to date. Especially formic acid and methanol [130,131] have attracted much interest due to their usefulness as fuels in Polymer Electrolyte Membrane direct liquid fuel cells [132] where liquid carbonaceous fuels are fed directly to the anode catalyst and are electrocatalytically oxidized in the anodic half-cell reaction to C02 and water according to... 

The presence of defects opens new pathways which significantly decrease the thermal stability of the reconstructed Rh(llO) surfaces [39]. Although the activity of electrochemical oxidation of carbon monoxide and methanol electro-oxidation can be increased by increasing surface steps on Pt nanoparticles, the oxygen reduction reaction activity of the 2-nm-sized Pt nanoparticle has been found insensitive to the step area, as shown in Fig. 20.3 [40], in contrast to the methanol oxidation reaction activity. 

Sugimoto W, Saida T, Takasu Y. 2006. Co-catalytic effect of nanostructured ruthenium oxide towards electro-oxidation of methanol and carbon monoxide. Electrochem Commun 8 411-415. 

Carbon monoxide is a key molecule in the electro-oxidation of Cl compounds and of many alcohols, since it is always produced by the dissociative chemisorption of the molecule, and since it may block the active catalytic sites. Therefore, its electrooxidation on platinum-based metals dispersed in an electron-conducting polymer, such as PAni, was investigated for a long time in our laboratory [8,28,34]. 

The kinetics of the electro-oxidation of graphite in molten KHSO4 to volatile compounds (carbon dioxide, carbon monoxide, and traces of sulfur dioxide) was studied in the range 180—320° C. The faradaic yield for carbon dioxide (4F per mol of carbon dioxide) is about 90%. The rds is the desorption of oxygen-containing intermediate species [91]. 

Photocatalytic decomposition of alcohol Electro-oxidation of hydrogen Electroreduction of oxygen Ammonia synthesis Carbon monoxide methanation Carbon monoxide methanation Carbon monoxide oxidation Propene hydrogenation Benzene hydrogenation Oxidation of ethylene Coal liquefaction Electroreduction of oxygen Dehydrogenation of butadiene... 

In this mechanism the adsorbed acetyl plays a key role and its further oxidation is favored by the addition to platinum of metal atoms more easily oxidizable at low potentials, such as Ru, Sn, Mo, etc. Other electrocatalysts were considered for the electro-oxidation of ethanol, such as rhodium, iridium [18] or gold [19], leading to similar results in acid medium. The oxidation of ethanol on rhodium proceeds mainly through the formation of acetic acid and carbon monoxide, which is further oxidized to carbon dioxide when the rhodium surface begins to oxidize, at 0.5-0.7 V/RHB [18]. On gold in acid medium the oxidation reaction leads mainly to the formation of acetaldehyde [19]. 

He C, Kunz HR, Fenton JM. Electro-oxidation of hydrogen with carbon monoxide on Pt/Ru-based ternary catalysts. J Electrochem Soc 2003 150 A1017-24. 

Igarashi H, Fujino T, Watanabe M. 1993. Hydrogen electro-oxidation on platinum catalysts in the presence of trace carbon monoxide. J Electroanal Chem 391 119-123. 

While many studies have been performed for the oxidation of methanol and carbon monoxide on supported catalyst systems [66,99-103] and Pt-Ru bulk alloys [61,104— 107], relatively few studies have been initiated on single-crystal platinum surfaces modihed with ruthenium. Of those performed these have largely involved the investigation of platinum single crystals modihed by ruthenium dosed electro-chemically [92,93] or spontaneously [80-82,90,91] from aqueous chloride solutions. This approach is discussed in Section 5.4. 

This mechanism of methanol electro-oxidation avoids any mention of a blocking carbon monoxide, that is, a carbon monoxide radical that is tightly bonded to the surface, taking no more part in the oxidation of methanol to carbon dioxide. But possibly builds up and gradually decreases the amount of the surface available for reaction. 

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